1. Resilience of On-site Wastewater Treatment Systems After an Extreme Storm Event Laura Kohler University of Colorado Boulder

3. Robustness ToTo T RECOVER Resilience System Performance (%) 100% PoPo Time

4. Robustness ToTo T RECOVER Resilience System Performance (%) 100% PoPo Time Focus of presentation: What is the vulnerability of OWTS performance to changes in weather and climate variables? OWTS Fragility

5. Improve risk communication about OWTS solutions compared to other sanitation alternatives to: Enable risk-informed planning decisions Advise risk mitigation Build institutional capacity to respond Objective:

6. Temperature & Precipitation Stream Flow

8. No. Major Repairs

10. R 2 =0.81 1 No. of Precip. Events (> 5 inches) 2 Total Annual Precip. (inches) 3 Max Annual Temp.

12. Projection for temperature and precipitation increases by end of 21 st century leading to weather impacted events such as the 2013 Boulder Flood

13. Boulder Creek Stream Flow Level (ft) Hourly Rainfall (inches) Major Flooding Moderate Flooding Stream Bank Full Stream Level Sep-11 Sep-12Sep-13Sep-14Sep-15 Sep-16 Sep-11 Sep-12Sep-13Sep-14Sep-15 Sep-16

15. Robustness ToTo T RECOVER Resilience System Performance (%) 100% PoPo Time OWTS Fragility

16. Robustness ToTo T RECOVER Resilience System Performance (%) 100% PoPo Time OWTS Fragility Rapidity Redundancy Resourceful- ness

17. Questions? Contact: Laura Kohler Laura.kohler@colorado.edu Acknowledgements This material is based upon work supported by the National Science Foundation under Grant No. 2012139999 Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation.